This invention relates to a capacitor discharge pulse system and particularly a capacitor discharge ignition system supplying high voltage pulses for firing of an internal combustion engine and the like.
In the driving of pulsed loads, a capacitor discharge system may be employed to establish appropriate high voltage pulse energy to the load. The capacitor is charged to the desired voltage level from any suitable source and then discharged into the load. For example, internal combustion engines used in an outboard motor, other recreational or non-recreational vehicle and the like, may advantageously operate with capacitor discharge ignition systems. The capacitor is suitably charged from a battery-converter unit or alternatively from a small alternator-rectifier unit driven in synchronism with the engine. A particularly satisfactory capacitor discharge ignition system for a multiple cylinder internal combustion engine is shown in U.S. Pat. No. 3,805,759 which issued Apr. 23, 1974, to Arthur O. Fitzner. In that system, an alternator is provided to charge a main firing capacitor which is discharged to the spark plugs through individual discharge circuits, each including a controlled rectifier or other gated switch device. The main pulse charging alternator is preferably constructed with separate high speed and low speed charging windings for regulated charging of the capacitor over the normal speed range and establish optimum operation of the engine. A separate trigger pulse generator has distributed trigger windings which are connected to sequentially fire individual controlled rectifiers in the discharge circuits for each of the spark plugs and thereby provide proper time spaced discharge of the capacitor to the appropriate spark plug for firing of the engine.
Although such systems have been widely employed and have particularly provided a highly improved and practical, commercial ignition system in two-cycle internal combustion engines for marine drives and the like, optimum engine ignition has not always been obtained. Problems of misfiring have been encountered in the higher numbered multiple cylinder two-cycle engines such as those with four cylinders and above, particularly at higher speeds.